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Configurable Air Transport resources

Airlift systems have been locked into an unchangeable design paradigm since before World War II. The reason for this is the insecurity of decision makers in deciding to try new ideas. This fault permeates the aerospace world because its core dependency on engineering innovation has been overshadowed by a lack of competition, short-term business profitability, and immense personal financial rewards for ignoring design and engineering innovation.

The basic concept of the Configuration Air Transport was advocated by Major General James Gavin following World War II. This was tried out with the Fairchild XC-120.

With colleagues at the Aeronautical Systems Center, Wright Patterns Air Force Base, we resurrected this concept to explore, both technically and operationally, a modern version of Gen. Gavin’s concept.

Video explaining the CAT concept:

This is a profesionally prepared 12-minute video that explains the CAT concept and shows the strategic and tactical versions of the CAT. This video is in the pubic domain.

Source: Air and Space Power Journal published by the United States Air Force Air University at Maxwell Air Force Base, AL, Fall, 2004; available online.

Article background: The concept of a “mother” aircraft capable of carrying a detachable cargo module originated with Major General James M. Gavin, United States Army, and was published in his book Airborne Warfare in 1947. A description of his ideas along with the pertinent illustrations from the book are located on this web site. When the article “Global Air Mobility and Persistent Airpower Operations” was written, while I was aware of the Fairchild prototype XC-120 aircraft that implemented General Gavin’s ideas, I did not become aware of his ideas until after this article was written.

My first conceptual design of a module carrying aircraft was developed in the mid-1990’s and resulted from my involvement with Air Force futures wargaming. For the scenarios considered, it was apparent that improved air mobility capabilities were needed. Responding to this need, I developed what was then called the Common Air Transport or CAT. This was envisioned as a flying wing aircraft capable of carrying a single large module. The module was sized to carry the same payload as a C-5 Galaxy. John Livingston, one of the aircraft conceptual designers at the Air Force Aeronautical Systems Center at Wright-Patterson Air Force Base, suggested a name change to the Configurable Air Transport. This, he successfully argued, better reflected the true multi-mission capability of the concept (and it maintained the CAT acronym).

This Air and Space Power Journal article examined the application of this larger CAT to the Air Force’s missions for airborne tankers, air mobility, and air power projection. The intent was to make a statement about the untapped potential of air mobility that has yet to be fully exploited by the Air Force.

Alternate source: Because the figures on the web source of the article are small, the entire Fall, 2004, issue of the Journal is available for download here. The figures are more easily seen.

Note: This paper was presented at the American Institute of Aeronautics and Astronautics (AIAA) 43rd Aerospace Sciences Meeting and Exhibit, 10-13 January 2005, Reno, NV

Note: The paper is 24 pages and is a 2.5 meg download. The presentation is 33 charts and is a 4 Meg download.

Abstract: This paper describes a concept of a large flying fuselage transport aircraft that carries the cargo or missionized payload in several large, detachable modules instead of carrying this cargo or payload internally as in current aircraft designs. The paper addresses the application of this concept to the global military airlift missions of air refueling, materiel transport, and persistent air power projection. The paper concludes with a brief discussion of the extension of this module-based aircraft design to other emerging military and commercial air transport needs.

Article background: After the Air and Space Power Journal article, described above, was written, I decided to develop a second iteration of the CAT concept. The original CAT concept carried only a single large module that was approximately 150 ft in length, 30 ft in width, and 19 ft in height. On reflection, this was seen as impractical for normal air operations and it was decided to downsize the module and make appropriate changes in the CAT configuration.

Besides the complexities of handling the large module, an important constraint of the original CAT design was that the width of the CAT’s main landing gear was too wide to permit the aircraft to taxi on the existing airports’ 50-ft wide taxiways. A key change in this updated configuration was the adoption of a module size that would be able to be carried on different sized aircraft. With the driving new air mobility requirement being defined by the Army’s air mobile Future Combat System, the new module size was now only slightly larger than the fuselage of a C-130 tactical transport aircraft. Based on this change, the new conceptual design of the larger or “strategic” CAT was developed. It is important to note that, like the first article, this conceptual design also represents a “back-of-the-envelope” sizing of the vehicle. A true conceptual design and analysis of the configuration was yet to be accomplished. This was later done and is the configuration shown in later presentations and videos.

This presentation was made at the 2006 Airlift Tanker Association Conference. The presentation is an 8 Meg download.

This is the PDF of the entire 188-chart presentation.

This presentation addressed the updated version of the CAT concept originally introduced at the 2005 AIAA conference noted above. The presentation addresses the Strategic CAT or S-CAT concept, the Theater CAT or T-CAT concept, and the Tactical VTOL CAT or V-CAT concept.